Alkyl and haloalkyl N,N-dialkyl-N-methylolphosphorodiamidates

ABSTRACT

Alkyl and haloalkyl N,N&#39;&#39;-dialkyl-N-methylolphosphorodiamidates, for example, methyl N,N&#39;&#39;-dimethyl-N,N&#39;&#39;dimethylolphosphorodiamidate, useful for rendering combustible cellulosic materials flame resistant.

United States 1 July 29, 1975 Int. Cl C07f 9/24; C08f 45/58 Field of Search 260/953 [56] References Cited UNITED STATES PATENTS 3,134,742 5/1964 Wismcr et a1 260/953 UX Primary Examiner-Anton H. Butto [57] ABSTRACT Alkyl and haloalkyl N,N '-dialkyl-N methylolphosphorodiamidates, for example, methyl N,N-dimethy1-N,N'-dimethylolphosphorodiamidate, useful for rendering combustible cellulosic materials flame resistant.

6 Claims, No Drawings ALKYL AND HALOALKYL N,N-I)IALKYL-N- METHYLOILPI'IOSPHORODIAMIDATES CROSS-REFERENCE TO RELATED APPLICATION This is a continuation-in-part of application Ser. No. 261,812 filed June 12, 1972 and abandoned July 2, I973.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to alkyl and haloalkyl N,N- dialkyl-N-methylolphosphorodiamidates.

2. Description of the Prior Art Phosphorus-containing compounds are well known for their ability to impart flame resistance to fabrics. Many of such prior art compounds may be undesirable as flame retardants for fabrics because they stiffen the fabric, because of their volatility which leads to their loss, at least partially, during any curing operation, because of their toxicity, because they must be employed in large quantities to impart any significant flame resistance to the fabric, or because they are not fast to laundering. Known flame retardants for fabrics include phosphorodiamidates. Such materials usually are employed in combination with aminoplast resin precondensates to achieve durability or fastness tolaundering. If the amount of aminoplast required is high, excessive and intolerable stiffening of the fabric may result.

British Pat. No. 799,606 discloses that textile fabrics can be made flame resistant with N-methylol derivatives of alkyl or aryl esters of phosphorodiamidic acid, the alkyl or aryl group optionally being substituted with, for example, halogen. Preferably, the diamidic acid derivative is employed in combination with an amino-aldehyde resin. Such diamidic acid compounds may be undesirable because they impart objectionable stiffness to the fabric, because they cannot be made up into storage stable solutions, because the washfastness of the flame resistance imparted to the fabric decreases with increasing age of the solution before application, or because the flame resistance imparted to the fabric is not durable to home bleaching. Moreover, such diamidates may be undesirably expensive, in pure form, if they are prepared from a phosphoryl chloride, an alcohol and ammonia, yielding the difficulty separable ammonium chloride as a byproduct.

US. Pat. No. 2,828,228 discloses the use of alkyl and haloalkyl phosphorodiamidates and monoamidates, with or without N-alkyl substituents, in combination with a methylolmelamine for rendering cellulosic fibers flame resistant. Such flame retardants may impart undesirable stiffness to the cellulosic fibers. Similar amidates are disclosed in British Pat. No. 790,663 for imparting flame resistance to cellulosic materials.

British Pat. No. 1,222,885 discloses as flame retardants for cellulosic materials, compounds or combinations of compounds which contain nitrogen and phosphorus. It further discloses that fabrics treated with such a compound or combination of compounds have a good degree of flame retardance if the nitrogen content is equal to or greater than 6% minus 4 times the phosphorus content and, preferably, is at least 2.5 times the phosphorus content, with the preferred emounts of nitrogen and phosphorus totaling at least 3.5%. based on the weight of fabric. Exemplary of compounds containing both nitrogen and phosphorus and phosphorodiamidates having the formula wherein R can be substituted or unsubstituted C alkyl.

US. Pat. No. 2,832,745 discloses the use of phosphorodiamidates in combination with an adduct of a polymerizable phosphate ester and a polymethylol amide, azine or azole for imparting flame resistance to flammable materials, and US. Pat. No. 2,971,929 discloses a five-component mixture for imparting flame resistance and water repellency to combustible materials, which mixture can include an alkyl N,N'-dialkylphosphorodiamidate.

German Pat. No. 1,009,629 discloses flame retarding phosphorus compounds which are obtained by treating phosphoric triamide with formaldehyde and methanol. The product, which includes phosphorus esters and hexamethylenetetramine, appears to lack durability to laundering.

SUMMARY OF THE INVENTION It is an object of this invention to provide compositions which are highly effective in imparting flame resistance to combustible cellulosic materials. Another object is to provide phosphorus-containing compositions which impart flame resistance to such cellulosic materials. Still another object is to provide flame resis tant cellulosic materials. A further object is to provide such flame resistant materials which are durable to laundering and bleaching operations. Another object is to provide compositions which impart flame resistance to combustible cellulosic fabrics without deleteriously affecting the physical appearance and hand of the fab ric. A still further object is to provide phosphoruscontaining compounds which can be formulated into storage stable liquids which are useful in imparting flame resistance to combustible cellulosic materials.

The above objects are fulfilled by the present invention which, in summary, resides in alkyl N,N'-dialky1- N-methylolphosphorodiamidates having the formula wherein R is C alkyl having 0-3 substituents selected from chloro and bromo, each of R and R when taken singly is selected from C alkyl and C chloroor bromoalkyl, R is H or CA alkyl, R is H or CH OR wherein R is H or C alkyl and R and R when taken conjointly is C alkylene, provided that all carbon atoms alpha to the amide nitrogen and ester oxygen atoms are free of halo substituents. The invention includes storage stable solutions which can be formulated from the aforesaid phosphorodiamidates, the process of applying such solutions, optionally containing aminoplast resin intermediates, to combustible cellulosic materials, such as fabrics, and the durably flame resistant cellulosic materials which are produced by such process.

DETAILED DESCRIPTION OF THE INVENTION dichloro-Z-methylQ-propyl, l-chloro-3-bromo-2- methyl-Z-propyl, l,3,4-trichloro-2-butyl, l,4-diehloro- 3bromo2-butyl, Z-chloroethyl, Z-bromoethyl, 2,2,2- trichloroethyl, Z-chloropropyl. Z-bromopropyl, 3 chloropropyl, 3-bromopropyl. 2,3-dichloropropyl, 2,3-

This invention is based upon the discovery that the alkyl and haloalkyl N,N'-dialkyl-N- dibromopropyl, 2-chloro-3-bromopropyl, 23- methylolphosphorodiamidates as defined above are chloropropyl, l,3-dichloro-Z-propyl, l,3-dibromo-2 more effective than prior art compounds of similar propyl and l-chloro-3-bromo-2-propyl. The most prestructure in imparting durable flame resistance to com f r oa y i l have 5 l n l m 1n 3 bustible cellulosic materials, such as fabrics, and that It) hlomlnc 11101115 Such 11S yU- fabrics can be treated with such compounds without P PYL hyl-2-m ylsubstantial alteration oftheir physical appearance, softdibromopropyl an -tbrom et yh- I-m y J- ness or hand. The increased effectiveness of the comdibromopropyl. pounds of this invention is believed to be due, at least R and R in the above formula can be the same or partially, to their lower volatility at the elevated tem different, preferably the Sam n each i leCted peratures encountered in the curing step conventionfro t y t hyl. n-propyl and isopr pyl g P Ihfi ally employed in fabric treating operations first two being preferred These alkyl groups can bear In the phosphorodiamidates of this invention as ala chlorine or bromine atom in the B or y relation to the ready defined, R can be selected from N-pentyl, isoattached nitrogen atom, that is, the halogen atom canpentyl, neopentyl, Z-methylbutyl, 3-methylbutyl, n- 2 not be attached to the carbon atom which is alpha to butyl, isobutyl, tertiary butyl, n propyl, isopropyl, ethyl the amide nitrogen atom. Examples of haloalkyl groups and methyl radicals, the latter two being preferred. It include l-bromo-Z-propyl, lchloro-2-propyl, 2- also can be selected from C to C haloalkyl radicals bromoethyl and, preferably, 2-chloroethyl. having I to 3 halogen atoms selected from chlorine and R and R can together (conjointly) constitute an albromine on carbon atoms in the ,8 and higher relation 35 kylene radical of 2 to 5 carbon atoms wherein the two to the attached oxygen, that is, on carbon atoms other fr valences ar ir- 21 ,2- r -r l i n to each other, than the one alpha to the ester oxygen atom. Preferred as in Lzethylene, ltzpropylenev L -p py haloalkyl radicals have 2 to 5 carbon atoms and l to 3 butylenc, -P y 2,4-butylene, Y A- halogen atoms on carbon atoms which are in at least butylene n 2,4-p n yl n The -p py dlradl' the B-position (that is, B-and farther removed) to the l i a pr f rr m in i n f R n R ester oxygen atom. Typical haloalkyl radicals include In the Preferred COmPOUTIdS Of this iflvefltiOn R i 2,2-bis(br0m0methyl)-3-bromopropyl, l- CH OR". In such event, R and R can be the same or (bromomcthyl)-2-methy]-2,3-dibr mopropyl 1. different although they preferably will be the same. R (bromomethyl)-l-methyl-2,3-dibromopropyl, 2- and R alkyl groups can be selected from tertiary butyl, (bromomethyl)2-methylpropyl, l(hromomethyl)-2,3- secondary butyl. n-buty1.is0p py -P PYL y n dibromopropyl, l-bromomethyl-2-bromopropyl, methyl, the latter two being preferred. l-methyl-2,3-dibromopropyl. Z-chlorobutyl, 2- Typical phosphorodiamidates of this invention inbromobutyl, 3-chloro-2-hutyl, 3-bromo- Z-butyl, lelude those of the above formula wherein the various chloro-2-butyl, l-bromo-Z-butyl, 4chloro-2-butyl, 4 R groups are as set forth in Table l. Compounds 8 to C l mbutyl, 4-bromobutyl, 2,3-dichloro2- 20 and 27 to 33 in the table are preferred and, of these, methylpropyl, 2-bromo-3-chloro-2methylpropyl, 1,3- l8 to 20 and 31 to 33 are especially useful.

TABLE I R R R2 R" R l. l,4-dichloro3-bromo-2butyl l-bromo2-propyl l bromo-IZ-propyl H CHQOH 2. l,3,4trichloro2-butyl lChloro-2propyl l-chloro 'bpropyl H CHZOH 3. ZJ-dibromopropyl methyl 'l-bromoethyl H H 4. 2,3-dihromopropyl lbromocthyl methyl H H 5. Z-chloropropyl methyl 2chloropropyl H H 6. Z-chloropropyl 2chloropropyl methyl H H 7. l,3-dichloro-2-propyl Z-chlorocthyl Z-chlorocthyl H H 8. 2,3-dichloropropyl 2-chlorocthyl methyl H CHZOH 9. Z-chlorocthyl ethyl methyl H CHQOH l0. ethyl methyl methyl H H l 1. methyl methyl methyl H CHQOH l2. Z-chlorocthyl methyl methyl H H l3. Z-chloroethyl ethyl ethyl H CH. ,OH l4. Z-chloroethyl trimcthylcnc H C'H2OH l 5. lchlorocthyl Z-chlorocthyl Z-chlorocthyl H (H-10H ltr. 2chlorocthyl ethyl ethyl H isohutoxymethyl l7. l,3-dich|oro-Z-propyl Z-chlorocthyl Z'chlorocthyl H CH- ,()H 1h. Z-chlorocthyl methyl methyl CH; CH2OCH;I l9. Z-chloroethyl methyl methyl H ('H2OH 2t). 2,3-tlihromopropyl methyl methyl H CH OH 21 l-mcthyL" -dibromopropyl methyl methyl H H 22 l-mcthyl-..,. -dibromopropyl methyl methyl H CHZOH 2 3. l-( bromomcthyl )-Z-bromopropyl methyl methyl H H 24. l-( hromomcthyl )Jbromopropyl methyl methyl H (H oH 25. l(bromomcthyl)-3.3-dibromopropyl methyl methyl H H 2t). l-(hromomcthyl)-Z.Rtlibromopropyl methyl methyl H CHQOH 27. l bromomcthyl l mcthyl'2,Ttlibromopropyl methyl methyl H H 28. lt-hromomcthyl l mcthyl 2,3-tlibro1nopropyl methyl methyl H ClLOH Z9. l-(bromomcthyll-Z-mcth)l Z 3tlibromopropyl methyl methyl H H 30. l t bromomethyl l l mcthyl l.Z-dihimnopropyl methyl methyl H CH OH 3 l. ll bistbromomethylj-R-bromopropyl methyl methyl H H 32. lZ-bisthromomcthyll-Z-hromopropyl methyl methyl H (HZOH 33. Z..'I-bis(hromomcthyl)J-bromupropyl trimethylenc H CHLOH The hydroxymethyl compounds of this invention can be made by reacting the appropriate non-methylolated phosphorodiamidate, obtainable by known procedures, and formaldehyde in a solvent for the reaction product, under acidic, neutral or basic conditions, preferably basic conditions. The solvent may be aqueous, nonaqueous or a mixture of aqueous and nonaqueous. For economic reasons it is preferably aqueous, with water serving as the essential solvent or as an extender of an organic solvent for the reaction product. A convenient form of formaldehyde for use in the methylolation is 37% aqueous formaldehyde. When the reaction is carried out under basic conditions, a convenient pH is 8-12, preferably 9-1 1. Any soluble alkalizing material can provide the desired basic pH, such as sodium silicate, sodium carbonate, trisodium phosphate and the like, but sodium hydroxide or potassium hydroxide is preferred. The reaction is carried out at O-30C., preferably 1020C.

Progress of the reaction can be followed by periodic broad band proton decoupled P-31 nuclear magnetic resonance (NMR) spectrum analyses of the reaction mixture using 85% phosphoric acid as the external standard. The noncyclic phosphorodiamidate starting materials have a characteristic band or multiplet of peaks in the range of -18 to 22 ppm. relative to the standard; as the methylol compound is formed, it peaks in the NMR spectrum shift toward the standard and show a shifted band of peaks centered in the range of to 19 ppm.

The ppm. values reported herein are given as negative values to indicate that the bands are shifted in a negative direction from the bands in 85% phosphoric acid which is the standard.

N,N'Alkylenephosphorodiamidates in a suitable solvent have characteristic peaks in the range of15.5 to 16.0 ppm.; the monomethylol derivative show shifted bands of peaks centered at about 1 3.9 to 14.9 ppm.; the dimethylol derivatives, at 12.2 to 13.2 ppm.

Typically, the P-31 NMR spectrum of solutions of 2- chloroethyl N,N'-dimethylphosphorodiamidate in water, methanol or chloroform changes from a peak at 2 111 ppm. (characteristic of the unmethylolated material in such solvents) to peaks in the range 19.4 to -16.1 ppm. (characteristic of the monoand dimethylol derivatives). The P-31 NMR spectrum of solutions of 3-chloropropyl N,N'dimethylphosphorodiamidate changes from a peak at 19.1 ppm. to a multiplet of peaks centered at -16.7 ppm. (characteristic of the dimethylol derivative). The P-31 NMR spectrum of solutions of 2,2,2-trichloroethyl N,N-dimethylphosphorodiamidate changes from a peak at 19.0 ppm. to a multiplet of peaks centered at 16.0 ppm. (characteristic of the dimethylol derivative). The P-31 NMR spectrum of solutions of 2,2bis(bromomethyl)-3- bromopropyl N,Ndimethylphosphorodiamidate changes from a peak at -19.6i0.1 ppm. to peaks at 182 and 17.6 ppm. characterizing the monomethylol derivative and to peaks at 16.3, 16.0 and 15.5 ppm. characterizing the dimethylol derivative. Aqueous solutions of 2-chloroethyl N,N'-trimethylenephosphorodiamidate have a P-31 NMR spectrum with a peak at 15.8 ppm.', this peak shifts to a band centered at about l4.4 ppm. for the monomethylol derivative and to about 12.7 ppm. for the dimethylol derivative. When the shifted band or multiplet of peaks becomes constant, the methylolation is complete.

The alkoxymethyl compounds of this invention can be made directly from the appropriate unmethylated phosphorodiamidate, obtainable by known means. and a chloromethyl ether CICH OR (R previously defined) in an alkaline medium, for example, at a pH of 812, preferably 9-1 1. The alkoxymethyl compounds also can be made by etherifying the previously described hydroxymethyl compounds with an alcohol R OH (R previously defined) in an acidic alcoholic medium, for example, at a pH of l-5, preferably 2-3. The formation of the alkoxymethyl compounds also can be followed by periodically monitoring the P-31 NMR spectrum during the reaction.

As indicated above, the phosphorodiamidate intermediates for making the compounds of this invention can be produced by known methods. For example, the ester portion of the compound can be provided by reacting an alkanol or a halogenated alkanol ROH (R previously defined) with a phosphoryl halide by a procedure such as disclosed in US. Pat. No. 2,716,657 or by G. M. Kosolapoff in Organophosphorus Compounds, John Wiley and Company (1950), or by reacting the phosphoryl halide and a 1,2-alkyleneimine employing a procedure such as disclosed by N. P. Grechkin in lzvest. Akad. Nauk S.S.S.R., Otdel, Khim, Nauk 1956, 538-43 or in Textile Research Journal, page 669, August, 1970. The use of phosphoryl halide in molar excess over the hydroxy compound favors monoesterification. The ester portion of the compound also can be provided by reacting cyclic ethers, optionally having appropriately positioned chlorine or bromine substituents, and phosphoryl halides by a known procedure such as disclosed in US. Pat. Nos. 1,936,985; 2,157,164; 2,610,978; and 2,716,657 or by Kosolapoff, supra, page 230. Cyclic ethers which are useful in such a reaction include 1,2-expoxides, such as ethylene oxide, propylene oxide, epichlorohydrin, epibromohydrin, 1,2- and 2,3-butylene oxides, 2- methylpropylene oxide and 1,4-dichloro-2,3-butylene oxide; 1,3-epoxides, such as 1,3-propylene oxide, 1,3- butylene oxide, 4-ch1oro-1,3-butylene oxide and 2-chloro-1,3-propylene oxide; and 1,4-cyclic oxides, such as tetrahydrofuran and its halogenated derivatives.

The phosphorus esters obtained as recited immediately above can be reacted with a primary amine to provide the diamide moieties. Such procedures also are well known, for example, as disclosed by Kosolapoff, supra, page 279, by Caven in the Journal of the Chemical Society 81, 1362 (1902) or by Micaelis in Annalen 326, 129 (1903).

The aforesaid procedures can be employed to produce symmetrical or unsymmetrical diamidates.

The compounds of this invention can be used directly as prepared (in the reaction medium), they can be isolated and subsequently placed in solution or they can be emulsified in aqueous media for application to a combustible cellulosic material. As initially prepared, based upon NMR evaluation and their effectiveness in imparting flame resistance, the compounds are stable in the reaction medium for several months. The isolated compounds are stable indefinitely. Isolation can be carried out by stripping off the solvent from the reaction medium. The compounds, viscous oils to soft solids, can be redissolved or emulsified in water and/or organic, preferably water soluble, solvents. A first class of water soluble organic solvents includes such solvents in which the compounds are soluble and which have boiling points above room temperature up to about 170C., preferably up to about 115C., for example, monohydric aliphatic alcohols of 1 to 4 carbon atoms, such as methyl, ethyl, isopropyl and butyl alcohols, ethylene glycol, monoethers of dihydric alcohols, such as methyl Cellosolve and ethyl Cellosolve, tetrahydrofuran, mand p-dioxane, acetone, methyl ethyl ketone, dimethyl sulfoxide, dimethylacetamide and dimethylformamide. A second class of water soluble solvents includes water soluble poly(oxyalkylene)ethers having molecular weights of 200 to 1,000, for example, poly- (oxyethylene) ethers, preferably of molecular weights 250 to 450, Such solvents serve as useful carrier solvents for applying the phosphorodiamidates to the combustible substrate. Preferably, the carrier solvent should be capable of swelling the combustible cellu losic material being rendered flame resistant to facilitate penetration of the cellulose by the phosphorodiamidate. Preferred organic solvents of the first class include methyl, ethyl and isopropyl alcohols and dimethylformamide. When the organic solvent is not completely misible with water, it is convenient to incorporate a dispersing agent and emulsify the phosphorodiamidate, solvent and water. The dispersing agent should function in alkaline, neutral and weakly acidic aqueous media. Typical agents are alkali metal salts of sulfated straight chain C to C fatty alcohols.

.The agents can be used in concentrations of 0.1 to

preferably 0.2 to 2% by weightv The flame resistance imparted to combustible cellulosic materials by a compound of this invention is mamde durable to laundering by fixing or curing the compound after it has been applied, as a solution or emulsion thereof, to the substrate. Curing is carried out for a sufficient time and at such a temperature that the compound of the invention is insolubilized in the substrate. Representative of such an operation, the substrate which is impregnated with a solution of a compound of this invention is dried at 20l C. Curing is effected at l50l90C., preferably at l60l80C., in the presence of an acidic curing catalyst for 2-10 minutes, preferably 2-4 minutes. Because of the nonvolatility of the compounds of this invention, drying and curing can be carried out readily in one step if desired. The catalyst usually is dissolved in the solution of phosphorodiamidate before the solution is applied to the material being treated. The amount of catalyst employed usually is 0.55 weight preferably l2.5%, based on the weight of solution.

Catalysts suitable for use in curing or fixation are those which are acidic and are not lost by volatilization at fixing temperatures. Typical catalysts include protonic and Lewis acids which include organic acids, such as oxalic acid, tartaric acid, glycolic acid, lactic acid, succinic acid, citric acid and malic acid, as well as inorganic acids, such as the ammonium salts of hydrochloric acid, phosphoric acid and sulfuric acid, and acid salts, such as zinc fluoborate, zinc chloride, zinc nitrate, magnesium chloride and magnesium nitrate. Other useful catalysts are the ammonium salts of the abovementioned organic acids and amine salts, such as the hydrochlorides of 2-amino-2-methyl-l-propanol and tris(2-hydroxyethyl)amine. The preferred catalysts include ammonium chloride and 2-amino-2-methyl-1- propanol hydrochloride.

When the phosphorodiamidates of this invention are used to impart a significant degree of flame resistance to combustible cellulosic materials, they usually are applied in combination with other agents conventional in the art for enhancing flamen resistance and for improving the durability of the effect. The phosphorodiamidates of this invention are applied to the cellulosic material, for example, fibers, in the form of liquid compositions or solutions to achieve good penetration into the cellulosic material. The liquid composition, generally comprises the phosphorodiamidate, a curing catalyst, an aminoplast resin precursor, more fully described below, and a carrier medium which can wet, penetrate and swell the cellulose and which does not interfere with fixation of the phosphorodiamidate. Other adjuvants, such as dispersing agents and nonionic wetting agents, may also be advantageously incorporated into the treating solution.

The liquid composition generally contains 5-80 weight 70, preferably 2060% of active ingredient. The active ingredient can be either a phosphorodiamidate of this invention or, preferably, a combination of such phosphorodiamidate with 0.25-0.5 its weight of an aminoplastic resin precursor, that is, the weight of aminoplast resin precursor is 2550% of the weight of the phosphordiamidate.

Aminoplast resin precursors or intermediates useful in combination are water soluble compounds containing at least two moles of condensed formaldehyde, for example, as N-hydroxymethyl groups or C alkyl ethers thereof. Typical of these aminoplast resin intermediates are polymethylol derivatives, and their partial or complete ethers, of amides, such as urea, thiourea, guanidine and dicyandiamide, Particular examples of these condensates include dimethylolurea, tetrame thylolurea, di(methoxymethyl)urea, dimethylol guanidine, trimethylol guanidine and dimethyloldicyandiamide.

Derivatives of substituted ureas can also be used, such as formaldehyde condensates, and their ethers, of ethyleneurea, methyleneurea, acetylenediurea, biuret, oxydimethyleneurea (uron) and iminodimethyleneurea (triazone). Particular examples of these condensates include dimethylolethyleneurea, dimethylolmethyleneurea, tetramethylolacetylenediurea, trimethylolbiuret, di(methoxymethyl)uron and di(methoxymethyl)triazone.

Derivatives of triazines, such as melamine, diaminotriazine, formoguanamine and 2-chloro-4,6- diaminotriazine, can also be used. These represent a preferred class of aminoplast resin intermediates. Specific examples include formaldehyde adducts such as diand trimethylolmelamine, optionally partially methylated, hexamethoxymelamine, tetramethyloldiaminotriazine and tetramethylol-2-chloro-4,6- diaminotriazine.

Aminoplast resin intermediates also can be formed from diazines and azoles. Typical of these are formaldehyde adducts of 2,4-diamino-l.3-diazine, guanazole and diaminopyrrole.

As indicated above, nonionic wetting agents may be incorporated into the liquid compositions to accelerate the wetting of the cellulosic material. Such wetting agents include polyethylene oxides, such as a phenol or monohydric or polyhydric aliphatic alcohol which has been polyoxyethylated with ethylene oxide, for example, polyoxyethylated phenol. Such wetting agents usually comprise 0.01-0.15 weight "/1 of the liquid composition.

Conveniently, the liquid compositions are prepared by forming solutions or emulsions of hydroxymethyl phosphorodiamidates or alkoxymethyl phosphorodiamidates in concentrated forms. This can be done by producing the hydroxymethyland alkoxymethylphosphorodiamidates in liquid carriers and then admixing therewith any other desired components prior to use of the mixtures as flame retardants. In many cases, the phosphorodiamidate simply can be stirred into a solvent medium containing formaldehyde, a sufficient amount of alkali metal hydroxide is then added and, after about 20 minutes at about 2030C., the hydroxymethyl derivative is produced. In some cases, a solution of phosphorodiamidate in an organic solvent can be mixed with an aqueous medium containing the desired amount of formadehyde, the expected total required amount of alkali metal hydroxide and, optionally, a dispersing agent. Subsequently, when needed, other desired components can be added to such concentrates to prepare liquid compositions which can carry the phosphorodimidate into cellulosic materials in the desired amount.

Any suitable method can be used to incorporate the liquid composition into the cellulosic material being treated. A sufficient amount of the composition should be applied to provide the desired amount of flame resistance. The amount of active ingredient, as above defined, should be -35 weight preferably -25%, of the weight of the dry cellulosic material being treated. The liquid composition can be applied as a squirted or air borne driven spray onto moving substrate. Preferably, the liquid composition or solution of active ingredient is applied, especially to fabrics, by a conventional padbath technique. Add-on or net pickup of solution usually is 2OO weight preferably -120%, based on the weight of substrate.

Cellulosic fabrics which are treated with the compounds of this invention are soft and the imparted flame resistance is durable to laundering and any bleaching treatment which may accompany laundering. The effectiveness of the compounds of this invention is believed to be due to the combination of alkyl or haloalkyl and methylol groups (or their ethers) on the diamidate nitrogen atoms. When the compounds of this invention are used in combination with aminoplast resin precursors, only small amounts of the latter are required, thus ensuring substantial retention of the hand of the fabric being treated.

The compounds of this invention are particularly effective on all forms of cellulose which swell and become flexible upon exposure to the carrier solvent (water or organic solvent as described above) used to prepare the solution or liquid composition. When complete penetration of the cellulosic material is achieved by the treating solution, the flame resistance is imparted throughout the material. Suitable cellulosic materials include natural fibers, purified wood pulp and rayon. In the textile field, natural fibers include cotton, the preferred fiber, linen, viscose rayon, cuprammonium rayon, jute, hemp and ramie. Such materials can be treated in the form of raw fiber, carded stock, rovings, thread, yan and felts as well as in the form of knitted and woven fabrics. Cellulosic materials which have been treated with the compounds of this invention are especially useful for tents, stage scenery, upholstery fabrics, Slipcovers, draperies, wearing apparel for personnel in close relation to fire or heat, bedding, nightclothes, tarpaulins, insulation, padding, rope, string and twine.

1n the following examples demonstrating the preparation and use ofthe compounds and compositions of this invention parts are by weight except where otherwise specified. Broad band proton decoupled P-31 NMR spectra are reported in ppm. relative to phosphoric acid in the manner previously described. Fabrics are allowed a 24-hour exposure to room temperature and humidity prior to being evaluated for flame resistance. The terms hand, padding, laundering, limiting oxygen indx (L01), vertical flame test (VFT) and char length refer to the following:

Hand: the softness of a treated fabric relative to untreated fabric as the control. It is graded subjectively here on a scale of 1 to 5 in which 5 signifies a softness and flexibility virtually indistinguishable from the control while 1 signifies great stiffness relative to the control.

Padding: wetting the fabric with the phosphorodiamidate solution and then running the wet fabric between rollers to squeeze out liquid which is in excess of the desired pickup on the fabric.

Laundering, also expressed as home washing (HW): exposing the fabric to a standard laundering cycle, employing a washing solution of grams of a commercial detergent (Tide) per 15 gallons of water, and

tumble drying the washed fabric.

Limiting Oxygen Index: determined with a 5-inch by 2-inch piece of fabric spread lengthwise in a vertical plane and supported along its vertical edges. The spread fabric is positioned inside a transparent circular (cylindrical) column open only at the top. The top of the column is one or more inches above the spread fabric. The interior of the column is provided with an upward flow, from its base, of a gaseous mixture of pure oxygen and pure nitrogen. The volume flow rate of each gas making up the mixture is instrumented and manually adjustable. To test fabric in this apparatus, the spread fabric is ignited from the top while gas mixture flows up the column. The flow rates of the nitrogen and oxygen are adjusted until the flame on the ignited fabric just goes out. The ratio of the volume flow of oxygen to the sum of the volume flows of oxygen and nitrogen is then calculated. This value, called the Limiting Oxygen Index (LOI), is the average of two determinations. As a standard of reference, untreated 8-02. cotton twill used in the following examples to test the effectiveness of the compounds of this invention has an LOI value of 0180:0002 and is completely burned up in the vertical flame test. Hence, any treated cotton having an LOI value of greater than 0.180 is considered to exhibit some flame resistance. Air contains about 21 mole percent oxygen; therefore, fabrics with LOl values below about 0.210 can be expected to burn freely in a candlelike manner (from the top to the bottom) in air. For commercial applications, an LOI value of at least about O.260O.27O is considered acceptable.

Vertical Flame Test and Char Length: carried out in a 12-inch by l2-inch cabinet 30 inches high and having a glass front. Gas circulation is provided by a 4-inch high opening beneath the glass fron and a 6-inch diameter baffled hole at the top of the cabinet. It is provided with holder brackets on which a specimen holder is hung. The specimen holder provides a 2-inch wide by 14-inch high vertical open space and vertical side clips to hold edges of fabric which span this open space. Samples are ignited by a 6-inch high Bunsen burner having a 0.375-inch inside diameter tube and a luminous flame 1.5 inches long. To conduct the test, a 2.75-

inch by -inch fabric sample is held in the specimen holder by its vertical edges and the specimen holder is hung centrally by the holder brackets. The igniting flame is applied so that 0.75 inch of the lower end of the fabric is in the flame. This exposure is continued for 3.0 seconds and the flame is removed. After the flame has extinguished itself, the sample is removed from the holder. A hook with an attached weight is inserted into the sample on one side of the charred area 0.25 inch from the outside edge and 0.25 inch from the lower edge. For 2.0 to 60-02. per square yard fabric, a 0.50- pound weight is used. The corner of the cloth at the opposite edge of the char from the load is gently raised until the sample and weight are clear of supporting surface. The length of the tear which occurs is measured (in inches) and reported as char length. Where char length is reported below, it is understood to have been determined by this procedure and to be an average value of 2 or 4 determinations and neither or none of the samples burns the entire length. If any one sample burns the entire length (BEL), both or all samples are so rated.

EXAMPLE 1 2-Chloroethyl N-N '-Dimethylol-N,N '-dimethylphosphorodiamidate Preparation 162 Parts of 37% aqueous formaldehyde (2 moles) were cooled to 10C. and adjusted to pH 10 with 30% aqueous sodium hydroxide. 186.6 Parts of 2- chloroethyl N,N'-dimethylphosphorodiamidate (1 mole) were added; additional sodium hydroxide was added simultaneously so as to maintain the pH of the reaction mixture at 710. The temperature was maintained at 10C. Thirty minutes after completion of the addition, sodium hydroxide again was added to reestablish a pH of 10. After standing overnight at 25C. the pH was 7-8. The reaction mixture was vacuum distilled at 10-20 mm. pressure at 5065C. until no further distillate was removed. The residual product was an extremely viscous, water soluble, oil. The P 31 NMR analysis of the product in water showed a multiplet of peaks centered at 'l6.4 ppm. This contrasted with the starting phosphorodiamidate which showed in water a multiplet centered at 21.0 ppm. Elemental analyses of the oil gave the following results. Calculated for C H ClN O P: C, 29.2; H, 6.5; Cl, 14.4; N, 11.4; P, 12.6. Found: C, 28.6; H, 6.0; Cl, 13.9; N, 10.8; P, 12.1.

EXAMPLE 2 Ethyl N,N -Dimethylol-N ,N -dimethylphosphorodiamidate Preparation The procedure of Example 1 was repeated except that 212 parts of ethyl N, N-dimethylphosphorodiamidate (1 mole) were substituted for the diamidate shown. The P-31 NMR analysis of the product in dimethyl sulfoxide showed a multiplet of peaks centered at -16.1 ppm., in contrast with the starting phosphorodiamidate which showed a multiplet centered at -l9.3 ppm. in dimethyl sulfoxide. Elemental analyses of the product, an oil, gave the following results. Calculated for C H N O P: C, 34.0; H, 8.1; N. 13.2; P, 14.6. Found: C, 32.5; H, 7.1; N, 12.7; P, 13.6.

EXAMPLE 3 3-Chloropropyl N,N-Dimethylol-N,N '-dimethylphosphorodiamidate Preparation Example 1 was repeated except that 260.6 parts of 3-chloropropyl N,N-dimethylphosphorodiamidate were substituted for the diamidate shown. The P-3l NMR analysis of the product in water showed a multi plet centered at l6.7 ppm., in contrast with the starting phosphorodiamidate which showed in water a multiplet centered at -21 .0 ppm. Elemental analyses of the product gave the following results. Calculated for C H ClN O P: C, 32.3; H, 7.0; Cl, 13.6; N, 10.8; P, 11.9. Found: C, 32.9; H, 6.7; Cl, 13.5; N, 10.6; P, 12.8.

EXAMPLE 4 1,3-Dichloro-2-propyl N,N-Dimethylol-N,N'-dimethylphosphorodiamidate Preparation EXAMPLE 5 2,2,2-Trichloroethyl N,N '-Dimethylol-N,N '-dimethylphosphorodiamidate Preparation Example 1 was repeated except that 255.4 parts of 2,2,2-trichloroethyl N,N'-dimethylphosphorodiamidate were substituted for the diamidate shown. The P3l NMR analysis of the product in a chloroform-hexafluorobenzene mixture showed a broad multiplet centered at 16.5 ppm., in contrast with the starting phosphorodiamidate which showed in chloroform a multiplet centered at l9.0 ppm. Elemental analyses of the product gave the following results. Calculated for C H Cl N O P: C, 22.8; H, 4.5; Cl, 33.7; N, 8.9; P, 9.8. Found: C, 23.0; H, 4.1: Cl, 32.6: N, 8.7; P, 7.6.

EXAMPLE 6 2-Chloroethyl N ,N '-Dimethylol-N ,N '-trimethylenephosphorodiamidate Preparation A solution of 395 parts (2 moles) of 2-chloroethyl phosphoric dichloride in 533 parts of methylene dichloride was added to a solution, held at 0C., of 148 parts (2 moles) of 1,3-diaminopropane and 404 parts (4 moles) of triethylamine in 4,000 parts of methylene dichloride. The mixture was allowed to warm to 20C. overnight, then to 40C., and filtered to remove solid triethylamine hydrochloride. The filtrate was vacuum distilled at 100 mm. Hg at up to 50C. until no further distillate was removed. The recovered solid 2- chloroethyl N,N-trimethylenephosphorodiamidate was submitted to elemental analayses with the follow- EXAMPLE 8 Treatment of Cotton Fabric with 2-Chloroethyl N,N-Dimethylol-N,N-dimethylphosphorodiamidate ing results. Calculated for C I-I ClN O P: c, 30.2; 1-1, 5 and Trimethylolmelamine Foundi C, N, Three aqueous padbaths were prepared and desigs The Product Th water Showed smgle P31 nated A, B and C, each containing, per 100 parts of so- NMR P at PP molecular weght was lution, 8 parts of trimethylolmelamine, 2 parts of amconfirmed by h gh ft-380111111011 mass spectrometry. 19 monium chloride (curing agent), and 10, 15 and 20 Parts of the cyclic diamidate wergodissglved in 17 (parts parts, respectively of 2 chloroethyl NN, dimethylol of 37%.aqueous formaldehyde queous so N,N'-dirnethylphosphorodiamidate. The baths were hvdroxide was added at 20 C. to produce a pH of 10,

padded onto 8-02. cotton twill fabric samples (correand the solution was allowed to stand overnight. The

. spondmgly designated A, B and C) to 100% pickup. P-3l NMR analysis of the product in water showed a The impregnated fabrics were dried for 10 mlnutes at multiplet of peak centered at 12.7 ppm., confirming o o I 100 C., cured for 4 mmutes at 165 C., sub ected to that 1t was the desired compound.

home washes and tumble-dried. Elemental analyses were carried out to determine add-ons of the phos- EXAMPLE 7 phorodiamidate. Table 3 shows the results of the evalu- Treatment of Cotton Fabric with Alkyl ati of the treated fabrics.

TABLE 3 Wt. Add-On Atomic Cl/P Ratio Char Length (inches) LOI After 10 Durability After After 10 After 10 After 10 Sample Initial Home Washes 10 Home Washes Initial Home Washes Initial Home Washes Initial Home Washes A 9.6 7.0 73% 1.04 0.96 4.25 6.63 .260 .257 B 14.0 10.8 78% 1.13 1.00 4.88 4.75 .285 .274 C 19.2 14.4 75% 1.12 0.98 3.75 4.25 .300 .284

N,N-Dimethylol-N,N-dimethylphosphorodiamidates EXAMPLE 9 and Aminoplast Resin Sixteen aqueous padbaths were prepared, each containing per 100 parts of solution, 8 parts of trimethylolmelamine, 2 parts of ammonium chloride and the num- Treatment of Cotton Fabric with 2-Chloroethyl N ,N '-Dimethylol-N ,N '-Trimethylenephosphorodiamidate and Trimethylolmelamine Two aqueous padbaths were prepared and desige of Parts h w" in Table 2 of f y N, nated A and B, each containing, per 100 parts of soludlmethylol-NsN (hmethylphosphorodlamldate- The tion, 16 parts of trimethylolmelamine, 1 part of baths were padded onto 4-0 2. cotton flannelette sam- 2 methy] 2 aminOpmpano] 1 hydrochtoride (curing P to 100% P p The lmpreghated fabrfes were agent) and 31 and 41.3 parts, respectively, of 2- dried for 10 minutes at 100C., cured for 4 mmutes at hl th l N,N-dimethylol-N,N'-trimethylene h 16 subjected to home washes and tumble-dried phorodia'midate. The pH of the padbaths was 6.5. Pad- Elemehtal analyses e cafned T determlhe ding, drying, curing and evaluation were carried out as Ohs of the phosphorodlamldate? mmahy and after 40 in Example 8. Table 4 shows the results of the evaluahome washes. In all cases, the mtrogen/phosphorus rai fth treated f b i tios, corrected for the nitrogen content due to the aminoplast resin, were substantially constant. The follow- TABLE 4 ing table shows the results of the evaluations of the treated fabric samples. Durability refers to the phos- A B phorodiamidate retained on the fabric after 40 home wt Add on of? washes. The alkyl groups shown in the table refer to the W 154 89 alkyl moiety of the alkyl N,N'-dimethylol-N,N'-dimepost cure prewash 1.54 1.85

after 1 home wash 1.52 1.90 lhylphqephorqdllmldate' A 5 length of after 10 home washes 1.53 1.86 lnches 1s consldered passable and 15 so lndicated 1n the w Addon fN table. Greater char lengths are designated as failing. as dried 6.50 6.46

' TABLE 2 .15; Wt. 7: Add-On Durability After Char Length LOI Alkyl Group Nominal Analysis 40 Home Washes Initial After 40 Home Washes Initial After 40 Home Washes ClCH- CH 12.5 10.7 66% Pass Fail .257 .246 C1CH CH 15.0 11.5 70% Pass Fail .260 .255 CICH CH 17.5 15.2 73% Pass Pass .270 .259 ClCH CI-I 20.0 17.3 5971 Pass Pass .274 .255 C1C1-I CH CH, 12.5 13.0 63% Fail Fail .267 .251 CICH CH CH, 15.0 15.9 Pass Pass .274 .257 C1CH CH. .CH 17.5 18.0 63% Pass Pass .283 .274 ClCH CH CH- 20.0 19.8 61% Pass Pass .288 .273 CH3CH2 12.5 Pass Fail .267 CI-IKCHZ 15.0 Pass Pass .256 CH CH 17.5 Pass Pass .271 CHHCHQ 20.0 Pass Pass .271 (CICHQQCH 12.5 12.4 78% Fail Fail .279 (CTCHZJQ H 15.0 16.6 6772 Pass Fail .276 (ClCHzhCH 17.5 18.8 6571 Pass Fail .293 (ClCI-I CH 20.0 20.7 68% Pass Pass .287

Treatment of Cotton Fabric with Z-Chloroethyl mm. of Hg, leaving an orange brown oil (208 g.) (n,, 1.5513) whose composition as 2,2-bis(bromomethyl)- 3-bromopropylphosphorodichloridate was confirmed by P-31 and proton NMR spectra.

B. A solution of 2,2-bis(bromomethyl)-3- bromopropylphosphorodichloridate (100 g.) in methylene chloride (500 ml.) was treated with 4 molar equivalents of methylamine at to C. Methylamine hydrochloride precipitated and was removed by filtration and the solution was washed with three 50 ml. portions of water and dried over anhydrous sodium sulfate. Removal of the methylene chloride under reduced pressure yielded a pale yellow oil (88 g.) which when triturated with water provided a solid which when ret y y phosph r dia dat 5 crystallized from n-butyl chloride melted at Four aqueous padbaths were prepared so that each 6800-69500 The Sohd was Confirmed to be contained, per 100 parts of solution, 1 part of Z-methyl- (BrcH2)3CCHZOP(O)(NHCHSlZ'HZO' calculated for 2-aminopropanol-l hydrochloride (curing agent) and C1H1HBY8N2O3P: 18-7; H1 62% Found: (:1 either or parts of 2-chloroethyl N,N-dimethylol- 18-4; H1 N,N'-dimethylphosphorodiamidate (DDPDA). To 20 A f of 9 f l each of two of the baths also were added 6 parts of bromopropyl'NiN 'dmethylphospharodlamldate trimethylolmelamine (TMM). The baths were padded draw (40 mole), 37% formaldehyde (15-1 8- onto 5-02. cotton flannelette samples to 120% pickup, 0-188 mole) and P PY alcohol was heated then dried, cured and evaluated as in previous exama Steamhath uhhl a Sohmoh waSPbtamed- The P ples. Table 5 shows the results of the evaluation of the of the 5O1ut10n was adlusted to wlth aqueouslNaoH treated fabrics. The table also shows the results of the and the sohmoh was allowefl to Stan-d Ovemlght at evaluation of fabrics padded with four other padbaths room temPerature after Standmg Overnight the P was in which 2-chloroethyl N,N-dimethylphosphorodiami- The Sopropyl alcohol water and umeacted date (DPDA) was used in place f DDPDA Char maldehyde were removed by dlstillation at 25 mm. of length was obtained by employing a three second igni- The resldllla was v h y l' tion and using the longer of the two tear lengths from P P f g 'dlmethylphos' two determinations. Durability refers to the of the P FQ Q (P31 M m lSOprOpanOl/water gas element N or C1) retained on the fabric after 10 exhibited at l.0/5.7/8.2 ratio of slnglets at 20.3 ppm). home Washes The compound was miscible with a 75/25 (by volume) TABLE 5 Initial Wt. 7: Loss on LOl Char Length Durability After Parts 1n Bath 7: Add-On Curing After 10 After l0 10 Home Washes DDPDA TMM DDPDA Initial Home Washes lnitial Home Washes P N Cl 15 O 18.2 0 .236 .221 BEL BEL (17 69 57 2O 0 23.6 .26l .230 4.75 BEL 66 64 55 15 o 18.9 0 .279 .261 3.25 2.75 85 9e 81 20 6 24.4 .235 .271 3.25 2.5 so 91 ex DPDA TMM DPDA l5 0 12.2 32 .247 .l96 BEL BEL 63 33 ll 20 O 17.9 25 .277 .213 2.75 BEL 61 39 ll 15 5 16.9 r .291 .229 2.75 BEL 53 5e 1e 20 (1 20.7 14 .312 .245 2.75 BEL e1 52 15 It can be seen that the DDPDA is superior in durability to DPDA. The superior durability and the improved hydrolytic stability of the bound halogen in DDPDA are believed due to the complete substitution of the diamidate nitrogens. it should be further noted that DDPDA is more completely used than DPDA, thereby avoiding waste of the material with attendant coating of equipment.

EXAMPLE ll 2,2-Bis( Bromornethyl )-3-Brom0mpropylN.N Dim ethylol-N ,N -Dimethylphospho rodiamidate A. A mixture of tribromoneopentyl alcohol (150 g., 0.467 mole), potassium chloride (0.3 g.) and phosphorous oxychloride (200 ml; 2.1 moles) was stirred at reflux (l05l 10C.) for about 2 hours (until evolution of hydrogen chloride ceased). The reaction mixture was allowed to cool to room temperature and stand overnight under nitrogen atmosphere. Unreacted phos phorous oxychloride was removed by distilling at 25 mixture of water and isopropanol and the resulting solution was stable for at least 1 month.

EXAMPLE 12 Use of 2,2-Bis(Bromomethyl)3-Bromopropyl-N,N'- DimethylolN,N'-Dimethylphosphorodiamidate (Dimethylolated in situ) were dissolved in the solution and pieces of4 02. cotton flannelette fabric were immediately padded with the solution. The wet pickup of the padding solution was 100-1 20%. based on weightof fabric. The treated fabrics were dried for 10 minutes at 100C. and then cured for 4 minutes at l60-l65C. The results of L01 and VFT tests and the durability to home washes in terms of phosphorus in the fabric are summarized in Table 6.

TABLE 6 1. Flame Retardant (7.) in Padhath 11. Durability Tests wt. 7: P on fabric after cure wt. "/1 P on fabric after 10 home washes (HW) 71 retained after 10 HW Flame Retardancy Tests 1. initial (after euro) 2. after 10 HW B. VFT (char length. in.)

1. initial (after cure) 2. after 10 HW EXAMPLE 13 2,3-Dibromopropyl-N ,N .-Dimethy1o1-N,N'-Dimethylphosphorodiamidate 1,340 G. (8.73 moles) of phosphorus oxychloride were added to 436 g. (20 moles) of 2,3-dibromopropyl alcohol containing 1 g. of potassium chloride and the mixture was refluxed for 3v hours; HCl evolution had then ceased. The mixture was vacuum stripped down to a pressure of 5 mm. of Hg. at 90C. 318 G. of the residue, 2,3-dibromopropylphosphorodichloridate, were diluted in 2 liters of methylene chloride and 1 18g. (3.8 moles) of methylamine were bubbled in while maintaining the temperature below C. After 2 hrs., the reaction product was vacuum stripped to mm. of Hg. at 90C. The product, a dark orange oil, was washed with 500 g. of water at 50C. and dried.

G. of this product as a 50% solution in isopropyl alcohol were stirred into 2 molar equivalents of aqueous formaldehyde, adjusted to pH 10.5 with aqueous NaOH and allowed to stand 1 hour at 25C. The resulting solution was adjusted to pH 7 with aqueous HCl. 12 G. of trimethylolmelamine were dissolved in the solution, followed by 0.5 of 2-methyl-2-aminopropanol-1 hydrochloride and the bath was made up with water to 50 g. The bath was padded on 4 02. cotton flannel to an add-on of 10% of the phoshorodiamidate and 12% of the resin, dried at 1 15C. for 6 minutes and cured at 165C. for 4 minutes. The cured flannel after 14 hours of detergent washing (deemed equivalent to 10 home washes) gave a char length in the vertical flame test of 1.8 inches.

EXAMPLE l5 2,2-Bis( Bromomethyl )-3-Bromopropyl-N ,N Dimethylol-N,N -Trimethylenephosphorodiamidate 1.340 G. (8.73 moles) of phosphorus oxychloride were added to 650 g. (2.0 moles) of tribromoneopentyl alcohol and l g. of KCl and the mixture was refluxed until HCl evolution ceased (3 hrs.). The resulting mixture containing tribromoneopentyl phosphorodichloridate was vacuum stripped down to 5 mm. of Hg. at C., leaving an orange brown oil characterized by P-31 NMR in chloroform by a single peak at 2.01

449.2 G. of tribromoneopentyl phosphorodichloridate were added to a solution at 0 to -10C. of 74 g. of 1,3-diaminopropane and 202 g. of triethylamine in 1,200 g. of methylene chloride. After standing 1 hour the mass was washed with 1,200 g. of water at 30C. The organic phase was vacuum strippd to 5 mm. of Hg. at 90C. By P-31 NMR analysis, the product showed a major peak in 50/50 methanol/water (by volume) at 13.5 ppm. and a minor peak at 17.3 ppm. (expected of substantially pure 2,2-bis(bromomethyl)-3- bromopropyl-N.N-trimethylenephosphorodiamidate This product was made into padbaths by adding a 60% solution of it in 50/50 water/isopropanol (by volume) to 2 molar equivalents of 37% aqueous formaldehyde adding 15% aqueous NaOH to pH 10.5, allowing the mixture to stand 1 hour at 25C., neutralizing the mixture with 10% aqueous HCl, dissolving trimethylolmelamine in the mixture and, after adding 1%, based on the bath weight, of 2-methyl-2-aminopropanol-l hydrochloride, making the bath up to weight with water. The baths were padded at pickup on 4 oz. cotton flannelette, dried 10 minutes at C. and cured 4 minutes at C.

The treated fabrics were analyzed for N and P and tested by LOI and VFT as initially cured and after 10 2,2-Bis(Bromomethyl)-3-Bromopropyl-N,N-Dimethylphosphorodiamidate in Combination with Resin 44.9 Parts of 2,2-bis(bromomethyl)-3-bromopropyl- N,N'-dimethylphosphorodiamidate, 41.3 parts of poly- (oxyethylene) ether of molecular weight 350 and 9.8 parts of 37.4% aqueous formaldehyde were mixed and warmed to 60C. to produce a clear solution; the solution was cooled and filtered to remove trace haze. A P-3l NMR spectrum of the solution showed a small peak at -l9.5 ppm. (believed to be unreacted starting phosphorodiamidate), a doublet at -18.4 and 17.8 ppm. and multiple absorption at -l6.8, 16.4, l6.2 and l5.7 ppm. A sample of this concentrate afforded the same spectrum after standing at room temperature for 9 weeks.

In separate vessels, according to formulation, trimethylolmelamine was dissolved in boiling water to produce clear solutions. 4%, Final bath weight basis, of the sodium salt of the monoester of sulfuric acid and a mixture of C fatty alcohols were dissolved in the solutions; appropriate amounts of the above phosphorodiamidate concentrate were then added. Just prior to use 1%, final bath weight basis. of 2-methyl-2- aminopropanoll hydrochloride was dissolved in the cooled solutions. 4 Oz. cotton flannel fabrics were padded in the vessels to 100% solution pickup, dried at 120C. for 3 minutes and then cured for 3 minutes, one piece from each vessel at 165C. another piece from each vessel at 180C. The fabrics were home washed 14 times and then tested for hand and char length by VFT. Varied bath components used and the char length (in inches) by VFT and hand after 14 home washes are shown in Table 8. Hand, as reported in the table, was determined qualitatively based on a scale in the order soft (S), good (G), fair (F), harsh (H) and poor (P).

It can be seen that the combination of -14 weight percent resin and l2-15 weight percent diamidate provides improvement in the hand of the cotton flannel without significant change of flamae retardancy.

5 1 claim:

1. Alkyl phosphorodiamidate having the formula R 0 R'- ll /N1| N\ R OR CH2OR" wherein R is C, alkyl having 0-3 substituents selected from chloro and bromo,

each of R and R when taken singly is selected from C alkyl and C chloroor bromoalkyl,

R is H, and

R is H or CH OR wherein R is H,

provided that all carbon atoms alpha to the amide nitrogen and ester oxygen atoms are free of halo substituents.

2. Phosphorodiamidate of claim 1 wherein R is 2- chloroethyl, each of R and R is methyl, R is H and 0 R is cu on.

3. Phosphorodiamidate of claim 1 wherein R is C haloalkyl having 13 bromo substituents,

4. Phosphorodiamidate of claim 3 wherein R is C haloalkyl having 3 bromo substituents, each of R and R is methyl, R is H and R is H or CH OH.

5. Phosphorodiamidate of claim 4 wherein R is 2,2- bis(bromomethyl)-3-bromopropyl.

6. Phosphorodiamidate of claim 1 wherein R is 2,2- bis(bromomethyl)-3-bromopropyl, each of R and R is methyl, R is H and R is CH OH. 

1. ALKYL PHOSPHORODIAMIDATE HAVING THE FORMULA
 2. Phosphorodiamidate of claim 1 wherein R is 2-chloroethyl, each of R1 and R2 is methyl, R3 is H and R4 is CH2OH.
 3. Phosphorodiamidate of claim 1 wherein R is C2 5 haloalkyl having 1-3 bromo substituents.
 4. Phosphorodiamidate of claim 3 wherein R is C5 haloalkyl having 3 bromo substituents, each of R1 and R2 is methyl, R3 is H and R4 is H or CH2OH.
 5. Phosphorodiamidate of claim 4 wherein R is 2,2-bis(bromomethyl)-3-bromopropyl.
 6. Phosphorodiamidate of claim 1 wherein R is 2,2-bis(bromomethyl)-3-bromopropyl, each of R1 and R2 is methyl, R3 is H and R4 is CH2OH. 